What is the recommended treatment for a patient with an anal fissure?

Treatment for Anal Fissure

Start all patients with conservative management consisting of increased fiber intake (25-30g daily), adequate fluid intake, and warm sitz baths 2-3 times daily, which heals approximately 50% of acute anal fissures within 10-14 days. 1

First-Line Conservative Management

• Increase dietary fiber to 25-30g daily through diet or fiber supplementation to soften stools and minimize anal trauma during defecation 1
• Ensure adequate fluid intake throughout the day to prevent constipation 1
• Prescribe warm sitz baths 2-3 times daily to promote internal anal sphincter relaxation 1
• Approximately 50% of acute anal fissures will heal with these conservative measures alone within 10-14 days 1

Second-Line Pharmacologic Treatment (If No Improvement After 2 Weeks)

Add compounded topical 0.3% nifedipine with 1.5% lidocaine applied three times daily for at least 6 weeks, which achieves 95% healing rates. 1

• The calcium channel blocker (nifedipine) reduces internal anal sphincter tone by blocking slow L-type calcium channels, increasing local blood flow to the ischemic ulcer 1
• Pain relief typically occurs after 14 days of treatment with this combination 1
• This approach avoids permanent alterations in continence while providing high healing rates 2

Alternative Pharmacologic Options

• Glyceryl trinitrate ointment can be considered with 25-50% healing rates, though headaches are a common side effect and recurrence rates are high (67% at 9 months for chronic fissures) 3, 4
• Botulinum toxin injection into the anal sphincter is nearly as effective as surgery without significant adverse effects, though it has no established role in acute fissure management 5, 6

Surgical Intervention (Third-Line)

Lateral internal sphincterotomy should only be considered for chronic fissures (>8 weeks) that have failed comprehensive medical management, or for acute fissures with severe, intractable pain. 1

• Lateral internal sphincterotomy achieves healing in more than 95% of cases with recurrence rates of only 1-3% 6
• Surgery carries a small but real risk of permanent fecal incontinence (reported rates vary from minimal to 10-30% with certain techniques) 1, 6
• Surgery should be offered to patients without incontinence risk factors who have severe, unrelenting pain and are willing to accept a small risk of incontinence for the highest likelihood of prompt healing 2

Critical Pitfalls to Avoid

• Manual anal dilatation is strongly contraindicated due to unacceptably high permanent incontinence rates of 10-30% 1, 5
• Hydrocortisone should not be used beyond 7 days due to risk of perianal skin thinning and atrophy, which can worsen the fissure 1
• Do not perform surgical treatment for acute anal fissures unless there is severe, intractable pain 5

Red Flags Requiring Further Evaluation

• Atypical fissure locations (lateral rather than posterior midline) require evaluation for Crohn's disease, inflammatory bowel disease, anal cancer, or occult perianal sepsis 3, 5
• Signs of chronicity including sentinel tag, hypertrophied papilla, fibrosis, or visualization of bare internal sphincter muscle warrant more aggressive treatment approaches 3, 5
• Failure to respond to conservative treatment after 2 weeks requires reassessment and consideration of topical calcium channel blockers 5
• No response after 8 weeks of comprehensive medical management warrants consideration of surgical referral 3, 5

Special Considerations for Pediatric Patients

• The same conservative approach applies, with age-appropriate fiber intake and stool softeners if dietary changes are insufficient 3
• Surgical interventions should be avoided in acute fissures in children and only considered for chronic fissures non-responsive after 8 weeks of conservative management 3
• Topical calcium channel blockers (diltiazem or nifedipine) can be used in children with healing rates of 65-95% 3